1. Field of the Invention
The present invention relates to a data processing apparatus capable of communicating with an information processing apparatus via a network and acquiring packets flowing through the network, and relates to a control method for the data processing apparatus and a storage medium storing a program for executing the control method.
2. Description of the Related Art
In recent years, various devices such as information processing apparatuses (e.g., personal computers (PCs)) and data processing apparatuses (e.g., copying machines and printers) are connected to an enterprise network, and the number of devices continues to increase. In addition, different networks are connected together. Thus, the scale of networks becomes larger. On the other hand, once a network failure occurs, there is a fear that a large number of devices connected to the network are affected and business operations are disturbed.
The cause of network failure is multiple such as an erroneous setting of a device connected to the network and an excess traffic. Thus, upon occurrence of a network failure, it is necessary to promptly locate the cause of the network failure and take an appropriate countermeasure. As effective means for locating the cause of network failure, it is generally known to acquire network packets and analyze the content thereof.
Heretofore, to acquire network packets, a dedicated PC must be connected to a network considered to have trouble and packet acquisition software must be executed on the PC. In recent years, however, some data processing apparatus has a packet acquisition function and is able to acquire and hold communication packets flowing through a network.
For example, Japanese Laid-open Patent Publication No. 2001-274806 discloses a technique of using a packet acquisition function of a data processing apparatus to acquire packets flowing through a network during a given time period, analyzing the acquired packets, and making a network setting of the data processing apparatus based on an analysis result.
As described above, it is known to use a data processing apparatus to acquire packets flowing through a network for a given time period or at a timing set by a user. With the packet acquisition of this type, it is unnecessary to provide and connect to a network a PC dedicated for packet acquisition to identify the cause of network failure relating to the data processing apparatus (e.g., a copying machine) such as a printing speed reduction, thereby making it possible to reduce the effort for investigation of the cause of network failure.
However, the conventional data processing apparatus having a packet acquisition function has a problem that it is difficult to acquire packets at an appropriate timing upon occurrence of a network failure relating to the data processing apparatus.
For example, in the case of a network failure where transmission of an image obtained by scanning an original from the data processing apparatus to a server on the network occasionally fails, image transmission can sometimes be performed successfully when the data processing apparatus acquires packets for investigation of the cause of the network failure. In that case, the cause of such occasional network failure cannot be identified.
To obviate this, it appears possible to continue the packet acquisition by the data processing apparatus until a network failure occurs. In that case, however, problems are posed that heavy load is applied to a CPU of the data processing apparatus, a large-capacity memory resource (hard disk) is required, the memory resource is consumed wastefully, and the ordinary operation of the data processing apparatus is adversely affected.